Cook stove construction



1946- c. M. BREED ETAL 2,395,532

COOK STOVE CONSTRUCTION Filed Aug. 3, 1942 5 Sheets-Sheet 1 INVENTORS CARROLL M.BREED By HERMAN KIRCHHOIFER ATTORNEYS FIGJ,

Feb. 26, 1946. v c. M. BREED ET.AL 2,395,532

COOK STOVE CONSTRUCTION v Filed Aug. 3, 1942 3 Sheets-Sheet 2 INVENTORS CARROLL M.BREED BY HERMAN K|RCH HOFER ATTORNEYS Feb. 26, me. c. M. BREED ETAL 2,395,532-

COOK STOVE CONSTRUCTION Filed Aug. 3, 1942 3 Sheets-Sheet 3 INVENTORS CARROLL M. BREED BY HERMAN KIRCHHOFER ATTORNEYS V Patented Feb. 26 1946 COOK STOVE CONSTRUCTION Carroll M. Breed and Herman Kirchhofer, Ypsilanti, Mich., assignors to United Stove Company, Ypsilanti, Mich., a corporation of Michigan Application August 3, 1942, Serial No. 453,404

Claims. (01. 12644) This invention relates generally to cook stoves having fl ype burners and refers more particularly to an improved oven heating arrangement for such stoves. I

It has been the usual practice in the manufacture of electric and gas burning cook stoves equipped with ovens to regulate the oven temperatures by a thermostat installed in a manner to vary the supply of the particular heat producing energy in response to temperature variations in the oven. The use of thermal controlled means to regulate the operation of the heating elements in an electrically heated oven and to regulate the flow of fluid in gasheated ovens has been found to be satisfactory for securing a wide range of different temperatures in the oven and for maintaining the temperature of the oven reasonably uniform at any one of the preselected temperatures in the range. This more or less satisfactory operation is perhaps due to the fact that theheat producing energy in both the above instances responds practically instantaneous to operation of the thermostat.

However, the principle of oven control briefly outlined above has proved very unsatisfactory when applied to liquid burning stoves of the type having a wick located in a channel supplied with theliquid fuelfrom a suitable source by the ac-.

tion of gravity. In applying the thermostat control principle to a liquid burning stove of the above type, the thermostat is employed to regulate the supply of liquid to the wick channel. The arrangement is such that if the temperature in the oven exceeds the preselected temperature, the thermostat closes a valve which shuts ofi further flow of fluid from the source to the wick fluid is supplied to the channel to raise the flame the required amount. Thus, it will be seen that the temperature in the oven will fluctuate over a relatively wide range and that it is practically impossible to maintain a uniform preselected temperature in the oven.

Moreover, in attempting to thermostatically control ovens heated. by liquid burners of the character set forth, difllculty has been encountered in maintaining temperaturesin the lower 3:

regions of the adjustable range without completely extinguishing one or more of the burners. Extinguishing one or more of the burners is, of course, objectionable especially in cases where it is desired to subsequently raise the oven temperature because it entails again igniting the burner.

The present invention contemplates overcoming all of the above objections by providing a liquid burner oven construction with means which not only renders it possible to secure and to more uniformly maintain any one of a number of preselected temperatures in the oven but, in addition, enables obtaining a sufliciently low temperature in the oven for all practical purposes without extinguishing any one of the burners.

In accordance with this invention, the oven temperature is controlled without the use of thermostats or equivalent thermal responsive means by merely relatively vertically adjusting the reservoir or source of supply and the burners to vary the elevation of the burner channels with respect to the level of the fluid in the reservoir. As a result, the quantity of fluid in the burner channels is increased or decreased depending upon the direction of relative adjustment and the flame of the burners is substantially instantaneously correspondingly effected.

Another object of this invention is to support the burners at different elevations so that at least one of the burners burns at a greater intensity than the other. This arrangement is largely responsible for the ability of burners to provide and maintain a uniformly low tempera, ture in the oven.

Still another object of this invention is to provide a control supported for manipulation at a convenient point remote from the burners and operatively connected to the burners for raising and lowering the same relative to the reservoir throughout predetermined increments of travel which correspond to different temperatures in the oven.

A further object of this invention is to provide means for directing the heat generated by the burners in the oven so that the heat is uniformly distributed even though one burner is burning at a different intensity than the other.

The foregoing, as well as other objects, will be made more apparent as this description proceeds, especially when considered in connection with the accompanying drawings, wherein:

Figure 1 is a front elevational, view of a stove constructed in accordance with this invention; Figure 2 is a side elevational view of the stove nular inwardly tapering wall 24. isapertured in the manner indicated in the draW- shown in Figure 1 with certain parts broken away for the sake of clearness;

Figure 3 is an enlarged front elevational view of the burners and support therefor;

Figure 4 is a sectional view taken on the line 44 of Figure 3;

Figure 5 is a sectional view taken on the line 55 of Figure 3;

Figure 6 is a rear elevational view of a part of the control operating mechanism;

" the channels 2|.

Figure '7 is a side elevational view of the conspace between the top of the base II and the bottom of the oven I2 forms a compartment I4 ofsufilcient dimension to receive the burner assembly I5 for the oven. Both the oven and the compartment I4 are adapted to be closed by the usual doors I 6 and II, respectively. The doors are suitably hingedly supported at their bottom edges in a manner to enable the same to be readily opened whenit is desired to gain access to the interior of the oven I2 and burner compartment I4. The burner assembly I5 is shown in Figures 1 to 4, inclusive, as comprising a support I9 and a plurality of burners 2i) fixed on the support I9. In the present instance, two burners are shown and these burners are of the wick oil burning type. Although any one of a number of accepted designs of wick type oil burners may be used, nevertheless, the one shown in the several figures of the drawings is preferred. In general, each burner 23 comprises an annular fuel retaining channel 2| and a burner drum 22 suitably supported at its lower end on the upper .end of the channel. The upper end of each annular channel 2| is closed by a flame spreader 23 in the form of a disc having the periphery seated on the upper edge of the inner flange of the channel and having the central portion dished in an upward direction to provide an an- The wall 24 ings to enable air to pass laterally outwardly across the upper end of the channel.

Upon reference to Figure 3 it will be noted that a rod 25 extends upwardly through the support I9 in concentric relation to the channel 2| and projects through the top wall of the flame spreader. The rod is secured to the support It and the upper end thereof is threaded to receive a clamping nut 26 which serves to secure theflame spreader 23 and the annular channel 2| of the wick and extends downwardly below the base of the channel 2I into the fuel supply conduit 2s.

The fuel supply conduits 29 of the two burners I are connected together by means of a T-shaped coupling 30 which is connected to a reservoir 3| by means of an intake conduit 32. The reservoir 3| is shown in Figure l as supported in a compartment 33 located adjacent the compartment I4 and adapted to be closed by a suitable door H. The reservoir is adapted to contain a supply of fuel to the level indicatedby the dot and dash line 35 and is supported on the dividing wall between the two compartments I4 and 33 at such an elevation with respect to the burner channels 2| that fuel flows by the action of gravity into With the construction described above it will be noted that the intensity of the flame of each burner may be varied by altering the elevation of the "burners with respect to the level 35 of the fuel in the reservoir 3i. In order to accomplish this result, the support I8. for both burners is vertically adjustable in the compartment I4 relative to the reservoir 3| in the compartment 33. In detail, the su ort I9 .is slidably mounted on a pair of sheet metal plates 36 having the lower ends rigidly secured to the base I I at points spaced from each other in thedirection oflength of the support I9 and having laterally outwardly projecting vertically spaced'ears 31 apertured for slidably receiving the rods 25. The inner surfaces of the plates 36 respectively slidably engage the base portions of a pair of inwardly opening channel shapeil brackets 38 having the'upp'er flanges 39 secured to the supact with suitable angle brackets 42 to support' the member I9 with the burners 20 thereon.- As shown particularly in Figure 3, the anglebrackets 42 are respectively securedto the base portions of the channels 38 and cooperate with th lower flanges lie on the channels 38 to respectivel enga e diametrically opposite sides of the two cams It follows from the above that rocking movement of the shaft 4| in opposite direetionsraises and lowers the burner support I 9 to vary the elevation of the burner channels 2! relative to the level 35 of the fuel in the reservoir 3|. In other words, rocking of the shaft 4I controls the quantity of fuel in the channels 2I of the burners and,

therefore, correspondingly controls the intensity of the flame generated by each burn r.

In the present instance, the shaft 4| is rocked by a rotatable control element 44 mounted on the stove for convenient manipulation by the operator. As shown in Figures 1 and 2, the control element is rotatably supported on the apron 45 which extends above the top of theoven at the back of the stove. The control element 44 comprises a knob 45' secured to suitable rock shaft 46 and having a pointer 41 adaptedto move along a scale 48 which is graduated in difierentdegrees of oven temperature. The rockshaft 43 is supported in a bracket 49 which, in turn, is welded or otherwise fixedly secured to the apron 45 and shaft 46 and is operated by the latter to reciprocate the rac'kSI.

The lower end of the rack is secured to the upper end of the rod 52 by means of an adjustable connection 53 and the lower end of the rod 52 is connected to one end of a bell crank lever 54. The lever 54 is pivotally supported intermediate its ends on a bracket 55 which is fixedly se cured to the base H of the stove within the compartment Hi. The free end of the bell crank lever is pivotally connected to one end of a link 56 having the opposite end pivotally connected to the lower end of an arm 51 having the upper end fixed to the rock shaft 4| intermediate the ends of the latter.

The above arrangement is such that rotation of the control 45 in a clockwise direction to increase the oven temperature lowers the rack 5| and rotates the cams 40 in a direction to lower the burners 20 with respect to the level 35 of the fuel in the reservoir 3|. On the other hand, rotation of. the control 45 in a counterclockwise direction to decrease the oven temperature raises the rack 5| and rotates the cams 40 in the opposite direction to raise the burners 20 with reference to the level 35 of the fuel in the reservoir 3|.

It follows from the above that the angular cations of the complementary cams 40 with renection 53 between the rack 5| and the rod 52. It

i will also be noted that the control 45' is yieldably held in any one of its various adjusted positions by means of a spring detent58. The spring detent 58 is in the form of a flat spring having one end rigidly secured to the bracket 49 and having the opposite end fashioned to successively engage in the notches 59 formed in one edge of the rack 5|. Each notch 59 in the rack 5| corresponds to one setting of the control 45' so that these notches cooperate with the detent 58 to hold the parts in any one of the preselected settings. Attention is also called at this time to the fact that an additional notch 60 is formed in the rack 5| adjacent the lower end of the latter. This notch corresponds to the off position noted on the indicating dial and cooperates with the detent to hold the parts in a position wherein the burner channels 2| are supported above the fuel level 35.

Raising and lowering of the burners 20 is permitted without interfering with the supply of fuel to the burners by forming the intake conduit 32 of a plurality of sections and by connecting the sections with swivels joints. Upon reference to Figure 8 it will be noted that the intake conduit is formed of three section 60', 6| and 62. The section 60"is connected directly to the reservoir 3| adjacent the bottom of the latter by means of a nipple 63 and is connected to the section 6| by means of a swivel joint 64. The arrangement is such as to permit the sections BI and 62 of the intake conduit 32 to swing upwardly and downwardly relative to the section 60' or relative to the reservoir 3|. The section 62 is connected to the free end of the section 6| by means of a swivel coupling 65 and is bent at right angles adjacent the free end for connection with the T-shaped coupling 3|). As a result, the :burners 20 and associated supply conduits 29 are permitted to. move upwardly and downwardly relative to the reservoir 3| without interfering with the fiow of fuel from the reservoir to the burners and without incorporating flexible conduits.

It has been stated above that difficulty has been encountered with burners of the type shown herein in maintaining oven temperatures in the lower portion of the range without completely ex in ui hing one of the burners. In accordance with thepresent invention, the above objection is overcome by supporting one burner at a lower elevation than the other and for this purpose the support I9 is recessed as at 66. This recess enables supporting the right hand burner (as viewed in Figures 1 and 3) below the left hand burner. This arrangement is such that when it is desired to operate the oven at the minimum or at relative low temperatures, the support I9 is raised to a point where the channel of the left hand burner assumes a position above the level of the fuel in the reservoir 3|. When this condition exists, only the p lot portion of the left hand burner is burning and the intensity of the flame generated by the right hand burner is substantially reduced. As a result, the oven may be maintained at relatively low temperatures without the necessity of extinguishing one of the burners.

Upon reference to Figure 2 it will be noted that the bottom wall 61 of the oven is formed The projection 10 is inclined with respect to a horizonal plane and is located above the burners with the lower end positioned abovethe lowermost burner and with the upper end positioned above the other burner. Also the rear wall H! of the V- shaped projection is inclined to a lesser degree than the front wall so that a substantial amount of heat is directed toward the rear of the oven. This construction insures uniform distribution of the heat throughout the oven and contributes materially to obtaining highly eflicient ovenpperation.

Operation When the control 45' is in a position wherein the point 41 registers with the off position on the indicator dial 48, the burners 20 are elevated to a position wherein the lower ends of the pilot wick sections 29 are above the fuel level 35. In other words, both burners are extinguished and must be lowered before they can be ignited.

Assuming that the parts are in the above position and that it is desired to heat the oven |2 to a temperature of approximatel 400 the operator merely turns the control 4-5 in a clockwise direction to register the indicator 4'! with the graduation on the dial 48 corresponding to the desired 400 temperature. When the control 45' is rotated in a clockwise direction, both the burners 22 are lowered through the mechanism previously described connecting the control to the cam rock shaft 4|. As stated above, the support 9 for both burners rests the base portions of the: channels-2| of both burners assume positions below the level 35 of the, fuel in the reservoir 3|. 'As a result, fuel is pe'rmittedto fiow'by gravity intothe. channels and more ,fuel is, of course, supplied 'to the right hand burner due. to its lower elevation; The two burners are then ignited. and the combined heat produced by the two burners willeventually raise the oven temperature to 400 which corresponds to the preselected setting. In other words, the relation between the control 45' and the complementary cams-40 is'such as to insure locating the burners in such relation to the oil level 35 that the combined intensity of the two burners is sufiicient to heat the oven to the 400 setting. Thus, the temperature of" theoven is controlled by adjusting the elevation of the two burners with respect to the. fuel level. in the reservoir 3| and this arrangement is.- not only more accurate, because of the characteristics of the fuel employed but is also simpler and less expensive to produce.

What we claimas our invention is:

l. A stove comprising a plurality of'fluid burners, a fluid reservoir communicating with said burnersand supported at such an elevation'with respect to the burners that fluid: flows by gravity to the burners, means for supportingsaid burners in 'fixed relation to each other at difierent'elevations with'respect to each other, and: means for relatively vertically adjusting the reservoir and burners to vary the elevation of the-level of. the I fluid in the reservoir with respect to' the elevations of said burners.

2. A stove" comprising a plurality of burners each having a channel for receiving the fluid, a reservoir communicating with the channels of the 'burners and supported at such an elevation with respect to the channels that fluid flows by gravity to said channels, a vertically adjustable member for supporting the burners'in fixed relation to each other at difierent elevationswith respect to each other, rotatable cam means supporting said member, and means accessible from apoint re mote from the burners for'rotating the cam means in; opposite, directions throughout predetermined increments of travel which correspond to. preselected temperatures.

3. A stove having an oven provided with an opening, in the bottom wall and having a plurality of fiuid'burners located below: the oven in registration with the opening, a fluid reservoir communicating with the burners and supported at such an elevation with respect to the burners that fluid flows by gravity into the burners, means for supporting the burners in fixed relation to each other at differentelevations with respectto each other and means for uniformly distributing the heat supplied by the burners throughout the oven. r

4. A stove having an oven provided with an opening in the-bottom wall and having a plurality of fluid burners located below'the' oven in registration with the opening, afluid reservoir communicatingwith the burners and supported at such an.elevationwithrespect to the burners that fluid flows by gravity into the burners, means for supporting the burners in fixed relation to each other at difierent elevations with respect to each other and baffle means located in the oven above the opening'for directing the greater heat supplied by the lowermost burner laterally toward the, portion of the oven served bythe other burner.

5. A stove comprising a plurality of burners each having a channel communicating with a depending supply conduit, an annular wick located in each channel and having a pilot extension projecting downwardly into the adjacent supply conduit, a fluidreservoir communicating with the supply conduits and supported at such, an elevation with respect to the channels that fluid flows by gravity into' the channels; means for supporting the burners in, fixed relation at different elevations with respect to each other and means for vertically adjusting the. burner 

